scispace - formally typeset
Search or ask a question
Topic

Platinum

About: Platinum is a research topic. Over the lifetime, 49675 publications have been published within this topic receiving 1150035 citations. The topic is also known as: Pt & element 78.


Papers
More filters
Journal ArticleDOI
TL;DR: A non-platinum group metal electrocatalyst with an active site devoid of any direct nitrogen coordination to iron that outperforms the benchmark platinum-based catalyst in alkaline media and is comparable to its best contemporaries in acidic media is reported.
Abstract: Replacement of noble metals in catalysts for cathodic oxygen reduction reaction with transition metals mostly create active sites based on a composite of nitrogen-coordinated transition metal in close concert with non-nitrogen-coordinated carbon-embedded metal atom clusters. Here we report a non-platinum group metal electrocatalyst with an active site devoid of any direct nitrogen coordination to iron that outperforms the benchmark platinum-based catalyst in alkaline media and is comparable to its best contemporaries in acidic media. In situ X-ray absorption spectroscopy in conjunction with ex situ microscopy clearly shows nitrided carbon fibres with embedded iron particles that are not directly involved in the oxygen reduction pathway. Instead, the reaction occurs primarily on the carbon-nitrogen structure in the outer skin of the nitrided carbon fibres. Implications include the potential of creating greater active site density and the potential elimination of any Fenton-type process involving exposed iron ions culminating in peroxide initiated free-radical formation.

563 citations

Journal ArticleDOI
TL;DR: The selectivities, sensitivities, and stabilities determined experimentally have demonstrated the potential of mesoporous platinum as a novel candidate for nonenzymatic glucose sensors.
Abstract: Roughness of nanoscopic dimensions can be used to selectively enhance the faradaic current of a sluggish reaction. Using this principle, we constructed mesoporous structures on the surfaces of pure platinum electrodes responding even more sensitively to glucose than to common interfering species, such as l-ascorbic acid and 4-acetamidophenol. Good sensitivities, as high as 9.6 μA cm-2 mM-1, were reproducibly observed in the presence of high concentration of chloride ion. The selectivities, sensitivities, and stabilities determined experimentally have demonstrated the potential of mesoporous platinum as a novel candidate for nonenzymatic glucose sensors.

562 citations

Journal ArticleDOI
TL;DR: The influence of the preparation methods on the catalytic activity for CO oxidation was markedly large for Au-TiO2 and negligible for Pt- TiO2 catalysts as discussed by the authors, and the most active catalysts for both Pt and Au were prepared by deposition-precipitation (DP), photodeposition (FD), and impregnation (IMP).
Abstract: The influence of the preparation methods on the catalytic activity for CO oxidation was markedly large for Au-TiO2 and negligible for Pt-TiO2 catalysts. Platinum and gold were deposited on TiO2 by deposition-precipitation (DP), photodeposition (FD) and impregnation (IMP). The DP method gave the most active catalysts for both Pt and Au. Gold catalysts prepared by DP were active at temperatures below 273 K and showed a much greater activity than Pt catalysts.

561 citations

Journal ArticleDOI
TL;DR: The results demonstrated that high-activity electrocatalysts can be devised that contain only a fractional amount of Pt and a very small amount of another noble metal.
Abstract: We synthesized a new class of O2 electrocatalysts with a high activity and very low noble metal content. They consist of Pt monolayers deposited on the surfaces of carbon-supported nonnoble metal−noble metal core−shell nanoparticles. These core−shell nanoparticles were formed by segregating the atoms of the noble metal on to the nanoparticles' surfaces at elevated temperatures. A Pt monolayer was deposited by galvanic displacement of a Cu monolayer deposited at underpotentials. The mass activity of all the three Pt monolayer electrocatalysts investigated, viz., Pt/Au/Ni, Pt/Pd/Co, and Pt/Pt/Co, is more than order of magnitude higher than that of a state-of-the-art commercial Pt/C electrocatalyst. Geometric effects in the Pt monolayer and the effects of PtOH coverage, revealed by electrochemical data, X-ray diffraction, and X-ray absorption spectroscopy data, appear to be the source of the enhanced catalytic activity. Our results demonstrated that high-activity electrocatalysts can be devised that contain ...

561 citations

Journal ArticleDOI
16 Oct 2012-ACS Nano
TL;DR: It is found that NG supported with 5 wt % Fe nanoparticles displayed an excellent methanol crossover effect and high current density in an alkaline solution, and Fe-incorporated NG showed almost four-electron transfer processes and superior stability in both alkaline and acidic solutions, which outperformed the platinum and NG-based catalysts.
Abstract: The high cost of platinum-based electrocatalysts for the oxygen reduction reaction (ORR) has hindered the practical application of fuel cells. Thanks to its unique chemical and structural properties, nitrogen-doped graphene (NG) is among the most promising metal-free catalysts for replacing platinum. In this work, we have developed a cost-effective synthesis of NG by using cyanamide as a nitrogen source and graphene oxide as a precursor, which led to high and controllable nitrogen contents (4.0% to 12.0%) after pyrolysis. NG thermally treated at 900 °C shows a stable methanol crossover effect, high current density (6.67 mA cm–2), and durability (∼87% after 10 000 cycles) when catalyzing ORR in alkaline solution. Further, iron (Fe) nanoparticles could be incorporated into NG with the aid of Fe(III) chloride in the synthetic process. This allows one to examine the influence of non-noble metals on the electrocatalytic performance. Remarkably, we found that NG supported with 5 wt % Fe nanoparticles displayed ...

558 citations


Network Information
Related Topics (5)
Oxide
213.4K papers, 3.6M citations
90% related
Catalysis
400.9K papers, 8.7M citations
90% related
Raman spectroscopy
122.6K papers, 2.8M citations
88% related
Aqueous solution
189.5K papers, 3.4M citations
88% related
Hydrogen
132.2K papers, 2.5M citations
87% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20231,041
20221,789
2021867
20201,180
20191,408
20181,449